A typical conventional apparatus for epitaxially growing a semiconductor crystal is shown, in a cross sectional view, in FIG. 1. Formed inside a quartz container 1 of a reactor 2 is a suscepter 4, for holding semiconductor substrate 3. Mounted on one inner side wall of the reactor 2 are a reactive gas supply tube 5 connected with a reactive gas supply source (not shown), while mounted on the other side wall is an exhaust tube 6 connected with an exhaust system (not shown).
The suscepter 4 which has a surface of highly pure carbon coated with silicon carbide and is mounted on the upper end of a shaft 8 hermetically mounted through the container 1 via a turning mechanism 7.
Formed in the upper end of the reactor 2 is a quartz window 9, over which is a quartz window 90 of an infrared lamp house 11 accommodating therein a multiplicity of infrared lamps 10.
The semiconductor substrate 3 is mounted on top of the suscepter 4, which is then rotated by the shaft 8. With a reactive gas 12 being supplied into the reactor 2 through the reactive gas supply tube 5, the infrared lamps 10 in the infrared lamp housing 11 are activated to thereby raise the temperature inside the reactor 2. The heated reactive gas then reacts with the surface portion of the semiconductor substrate 3, forming a thin layer of semiconductor layer. After the growth, the reactive gas remaining in the reactor 2 is exhausted through the exhaust tube 6.
Although a crystal layer may be formed on the semiconductor substrate in such a conventional apparatuses as mentioned above, the apparatuses have disadvantages in that the turning mechanism 7 is exposed in the reactor 2, giving off dust from its shaft into the reactor 2, which dust can be deposited on the semiconductor substrate 3, causing a contamination of the crystal grown on the semiconductor substrate 3. Such a turning mechanism is utilized in the prior art since the suscepter 4 must be rotated in order to make the temperature distribution of the semiconductor substrate 3 uniform.
The conventional apparatuses have a further disadvantage that the reactive gas 12 will have a turbulent flow 13 over the semiconductor substrate 3 because of the rotation of the suscepter 4 by the shaft 8, so that the uniformity of the crystal layer formed on the semiconductor substrate 3 is decreased.